Database schema migration for SQLAlchemy

Inspired by Ruby on Rails' migrations, migrate provides a way to deal
with database schema changes in SQLAlchemy projects.

SQLAlchemy-migrate is build on top of SQLAlchemy and provides a changeset
and a versioning API for database schemas as well as a script utilizing
these APIs. The database change sets are managed in a file based
repository allowing upgrades and downgrades of database schema versions.
The change sets may consist of Python code facilitating the changeset API
or SQL scripts.

SQLAlchemy-migrate has support for MySQL, PostgreSQL, SQLite and Oracle
databases. The support for Oracle is not as well tested as the support for
the other database systems.